Typo-fixes (#1244)

docs/prerequisites/broker.md

@@ -11,9 +11,9 @@ There is many choice of brokers, here is some of the most populars:
 
 This [wikipedia list](https://en.wikipedia.org/wiki/Comparison_of_MQTT_implementations) gives you more details about the different choices you have.
 This [github list](https://github.com/mqtt/mqtt.github.io/wiki/libraries) seems to be the most exhaustive ones.
-Here is also some [idea of criterias](https://www.hivemq.com/blog/top-10-mqtt-broker-criteria/) from HiveMQ.
+Here is also some [ideas of criteria](https://www.hivemq.com/blog/top-10-mqtt-broker-criteria/) from HiveMQ.
 
-Once your broker installed it can be interesting to see the traffic passing to it and to publish data, so as to do that there is several tools available:
+Once your broker is installed it can be interesting to see the traffic passing to it and to publish data, so as to do that there are several tools available:
 * [MQTT Explorer](http://mqtt-explorer.com/)
 * [HIVE MQ Web client](https://github.com/hivemq/hivemq-mqtt-web-client)
 * [MQTT FX](https://mqttfx.jensd.de/)